Automatic transmission



Y pnl 7, 1936. c. F. RAUEN ET AL 2,036,500

AUTOMATIC TRANSMISSION Filed Nov. 4, 1933 2 Sheets-Sheet l QN N WN IN1/EN /Paaen Kei Z er ,m0/LAN ATTO EY.

I I I II III I Il l' "O I! o Il Cari F.

c. F. RAUEN ET AL 2,036,500

Filed Nov. 4, 1933 2 Sheets-Sheet 2 C r( au n,

,006A Rex /I/eZZer. ff@

E E mmm.

Patented Apr. 7, '1936 UNITEDI STATES PATENT OFFICE AUTOMATIC TRANSMISSION Application November 4, 1933, Serial No. 69,6,626

Claims. (Ci. 74`336) Our invention relates to automatic transmissions or speed changing mechanisms and, as i1- lustrated, is particularly adapted for use in automotive vehicles. Our invention contemplates the matically effected under any one of' a plurality.

of predetermined conditions of operation. Another object of oui,` invention is to provide a transmission inwhich free wheeling and positive drives are provided in all forward speeds. Another object of our invention is to provide a transmission in which a change from any one driving ratio to any other next succeeding driv' ing ratio may be eifected at any time,

Another object of our invention is to provide' in a transmission, in which normally a change in the driving ratio may be automatically effected under any one of a plurality of predetermined conditions of operation, means for manually effecting a change in the driving ratio without re- Iglxrd to the automatic speed changing'mecham. s l, -Other objects and advantages will appear from the following specification with reference to the accompanying drawings of` which there are two sheets, and in which: Fig. 1 is a diagrammatic view illustrating an automotive vehicle in which our automatic transmission has been incorporated;

Fig. 2 is a longitudinal view partlyin section, disclosing. the internal constructiony of our automatic transmission;

Fig. 3 is a top plan view of the yoke rod mechanism for the transmission illustrated in Fig. 2;

Fig. 4 is a vertical cross-sectional view taken on the line 4--4 of Fig. 2 and looking in the direction of the arrows and illustrating the constructional details of an overrunning or free wheeling Fig. 5 is a vertical cross-sectional view taken on the line 5-5 of Fig. 2, looking in the direction of the arrows and illustrating the constructional details of the automatic clutch or speed chang- 55 ing mechanism; and

Fig. 6 is a diagrammatic view of the different positions for the handle of the gear shift lever.

Referring to Fig. 1 of the drawings, there is shown a diagrammatic view of a portion of an automotive vehicle comprising a main frame 5 member i0 providing a suitable support for an engine l2, a housing-enclosed clutch I4, a transmission indicated generally at i5, a propeller shaft i 8 connected through a universal joint 20 tothe driven shaft 22 of the transmission, and a 10 shift lever 24 providing a manual control f or the transmission. An engine throttle control 25 is provided for regulating the speed of theengine i 2. The transmission I6 in general comprises a. casing 26 providing a housing for enclosing the l5 operating' mechanism of the transmission, a cover plate 28 providing a support for the shift lever 24, a driving shaft 30 connected to the engine through the housing-enclosedclutch I4, a driven shaft 22, and suitable gearing for providing 20 a plurality of different driving connections between the driving shaft 30 and the driven shaft 22.

Having reference now to Fig. 2, the driving shaft 30 is journaled in a bearing 32 suitably secured in an aperture provided in the forward 25 Wall of the casing 26. The driven shaft `22 at its forward end is journaled in a bearing 34 secured in a counterbore of the driving shaft 30, and at its rearward endis journaled in a bearing 36 suitably secured in an aperture in the rearward 30 wall of the casing 26. A countershaft 38 is secured in the vforward and rearward walls of the casing 2S .and against rotation and has rotatably :lounted thereon a cluster of gears 4U, 42, 44 and 35 A portion of the driving shaft 30 adjacent one end thereof and within the casing 26 may be formed to provide a helical gear 48 which is adapted constantly to mesh with helical gear 40 on the countershaft for the purpose of rotating 40 the cluster of gears whenever the engine is operating and-the driving shaft 30 is connected thereto. An elongated sleeve 50 is slidably splined to the driven shaft 22 and carries freely mounted thereon a gear 52 provided with two sets of ex- 45 ternal radial teeth 54 and 55 and internal splines 58. Sleeve 50 is provided with a plurality of sets of external radial teeth 6B, 52, and 54. Gear 52 is adapted to be moved to the left, looking at Fig. 2, to mesh teeth 54 with the teeth on an 50 idler gear 66, which is rotatably mounted on a shaft suitably supported within the casing 25 and which is in constant mesh with gear 42 on the countershaft, and to mesh splines 58 with teeth 62 on the sleeve for the purpose of providing a 55 reverse driving connection between the shafts 30 and 22 through the intermediary of helical gears 48 and 40, gears 42, 68, and 54, and sleevev50 which is splined to the driven shaft 22.

An internally toothed annulus 'locked to the sleeve 50 through the medium of teeth 84 and secured against lateral displacement"- by snap rings 65 comprises the driven member of an overrunning or free-wheeling clutch indicated generally at 10. A series of spring pressed rollers 12 are adapted to wedge between cammed sur'- faces 14 uniformly disposed about the periphery of the annulus 68 and the inner surface of the driving member or shell 16 -of the overrunning clutch mechanism for the purpose of driving the annulus 68 with the shell 16 when the shell 16 tends to rotate counter-clockwise with respect to the annulus 68, looking at Fig. 4, and to permit the annulus S8 to rotate counter-clockwise with respect to the shell 16. Washers 18 and snap ring 80 serve to confine the rollers 12 in position and to retain the shell 16 in place relative to the annulus 68. Shell 16 is provided at its opposite ends, with sets of internal radial teeth 82 and 84 and with an external annular groove 86 which is adapted to receive a shift fork 88.

Movement of the gear 52 to the right, looking at Fig. 2, until teeth 56 thereof mesh with internal radial teeth 82 on the shell 16 of the overrunning clutch will mesh teeth 54 with those of the gear 44 for providing a low speed, one-Way or free wheeling drive between the driving and driven shaft and through the intermediaryof helical gears 48 and 40, gears 44 and 52, overrunning clutch 18, and .sleeve 50 which is splined to the driven shaft. Further movement of the gear 52 to the right to mesh splines 58 with teeth 04 is adapted to provide a two-way or positive low speed drive between the driving and driven shaft and through the intermediary just described with the exception that the overrunning clutch 10 is now locked out, due to the engagement of spline 58 with teeth 64 on the sleeve 50. A shift fork 80, depending from a collar 92 rigidly secured to a yoke rod 94 slidablysecured in the forward and rearward walls of the casing 26, is provided for moving the gear 52 either to the left on the right, looking at Fig. 2.

Yoke rod 94 is provided with a series of notches '66, 88, |00 and |02 corresponding respectively with the positive low, free wheeling low, neutral and reverse positions of the yoke rod and which are adapted to be engaged by a spring pressed poppet or detent secured in the forward wall of the casing 26 for thev purpose of locating the different positions of the yoke rod and for holding the same against undesirable movement; A second yoke rod |06 slidably secured in the forward and rearward walls of the transmission casing carries the shift fork 88 and has xedly secured thereto a collar |08 providing a gate H0 for recei'ving the lower end of the gear shift lever. The yoke rod L06 is provided on its under side with a series of notches H2, H4.' IIS, ||8 and |20 corresponding 'respectively with the positive second, free wheeling second, neutral, automatic and positive high positions cf the yoke rod and which are adapted to be engaged by a spring pressed poppet |04 which is secured in the forward wall of the transmission casing 26. The

bottom end of the gear shift lever 24 is adapted t to enter gate H0 for the purpose of moving the yoke rod |08 and to enter gate |22 provided in the collar 92 for the purpose of moving the yoke rod 84, for the purpose of manually selecting any desired gear position. .A

An intermediate speedhelical gear |30 is rotatably mounted upon. the driven shaft 22 and secured against lateral displacement thereon by suitable lrhrust members |32 and is provided with two sets of external radial teeth |34 and |38 and a set of internal radial teeth |38.

A high speed overrunning clutch indicated generally at |40 and similar in construction and operation to the .overrunning clutch indicated generally at 'i0 comprises an internally toothed driving member |42 secured to the end of the driving shaft 30 and a driven member |44. The overrunning clutch |40 comprises the driving member of an automatic clutch indicated generally at |50. The driving member of the automatic clutch comprises a drum-shaped member ers |52 and |54 and snap ring |56 are adapted l to position and hold the core |48 within the drumshaped member |44. The core |48 is provided with an internal set of teeth |58 which are adapted to mesh with teeth 82 on the sleeve 50 when the latter is moved to the left. The driving member |42 of the overrunning clutch |40 is provided with an internal set of teeth |60 which are adapted to mesh with teeth 60 on the sleeve 50 when the latter is moved to its leftmost position, looking at Fig. 2.

Each of the bolts |46 is slidably mounted in a radial groove or slot |60, a series of which are provided in the core ordriven member |48. Each of the bolts v|415 is provided with a transverse bore |62 adjacent one end thereof and a oentrallydisposed longitudinal bore |64. in which a plug. |06 is threadedly secured. A pin |08 car- 'ried by the core |48 projects into the transverse bore |62 and conines between a flatted surface of the pin and the threaded lplug |66, a spring |10 which tends to hold. the bolt in its inner or retracted position. The position of the plug may be adjusted for varying the tension of the Serine Each bolt is further provided with a notch on other. As shown in Fig. 5, a spring pressed pop- ,each face thereof and offset with respect to each pet |16 backed by an adjustable plug |18 and carried bythe core |48 is in engagement with notch |14 of the bolt |46. .Bolts |46 are movable outwardly under the` influence of centrifugal force resulting from rotation of the core or driven member |48. The tension ci' the spring tion for the purpose of holding the bolt against.

inward movement until'the tension of the spring |10 is greater than the centrifugal force resulting from rotation of the 'core |48 and the force with which the poppet engages the notch |12.'

The poppet |88 may be adjusted for varying the speed of rotation of the core |48 at which the bolt will return to its retracted position. Due to the shifting of the center of gravity, of the bolt |46 away from the axis of rotation, the bolt |48 norm-.ally will return to its retracted position at a. lower speed of rotation of the core |48 than that at which it is movable outwardly. The poppet l|88 has the effect of still further reducing the speed at which the bolt is movable inwardly which also serves to increase the differential between thespeed at which the b'olt is movable outwardly and inwardly.

The automatic clutch |58, as embodied in the transmission illustrated in Fig. 2, is adapted automatically to effect a change in the driving speed ratio from an intermediatefree wheeling drive to a high speed free wheeling drive, or from a high speed free wheeling drive to an interme rdiate speed free wheeling drive. The automatic shift from intermediate to high is effected when the speed of rotation of the core or driven member |48 is sufdcient to move one of the bolts |46 outwardly into one of the slots |41 in the member |44. It will be observed that the driving member |44 of the automatic clutch is provided with a greater number of slots |41 than is the driven member |48 provided with bolts |48. On this account only one of the bolts |46 can be in a projected position at any one time, because the other bolts are not at that same time, lined up with a slot in the driving memler. It will be apparent that when the transmission is in intermediate speed ratio that the driving .member |44 will be rotating at engine speed and the driven member |48 will be rotating at an intermediate speed, being connected to the driving shaft though the intermediary of teeth 62 on the /sleeve 58, meshing with the teeth |58 on the core |48, overrunning clutch 18, teeth 84 thereon meshlng with the teeth |34 on the intermediate speed helical gear |38 which is in constant mesh with the helical gear 46 of the countershaft, and gear 48 which is in constant mesh with the gear 48 of the driving shaft 38.

When the transmission is' in an intermediate speed ratio, the" driving member |44 of the automatic clutch will have a relative clockwise rotation with respect to the driven member |48 which is rotating at a'slower rate of speed. If the speed at which the core |48 is rotating is suicient to generate enough centrifugal force to overcome the tension of the spring |18 and of the poppet |16, the bolt |48 will tend to fly outwardly.

Each of the bolts |48 is provided with a tapered or beveled circumferential face |84 which causes 1 the bolts |48 to jump the slots |41 whenever the speed of rotation of the member |44 is substantially greater than that of the member |48. When the speed of rotation of the member |44 is decelerated relative to that of the member |48 until the members are rotating at approximately the same rate of speed, one of the bolts 48 will be projected into one of the slots |41 for the purpose of connecting the members |44 and |48 together and thereby driving the driven shaft directly with the driving shaft through the intermediary of overrunning clutch |48, automatic clutch |58 and sleeve 58 which is in engagement with the member 848 of the automatic clutch through the engagement of teeth 82 and teeth |58 and which is splined to the driven shaft 22. I

The overrunning clutch 18 permits the driven shaft 22 to overrun the intermediate speed gear it) when the transmission is in automatic high driving ratio. In order to place the gear of the transmission in a position where the automatic shift from intermediate to high may be effected,

4the overrunning clutch 18 is shifted to the left,

looking at Fig. 2, until the teeth 84 thereof are in mesh with the teeth |34 carried by the intermediate speed helical gear |38, when the teeth 82 on the sleeve 58 will be in mesh with the teeth |58 of the driven member |48 of the automatic clutch. After the speed of rotation of the driven member |48 is sufficient to move the bolts |46 radially outwardly, the speed of rotation of the driving member 44 may be reduced relative to that of the driven member by a temporary closing of the engine throttle, whereupon the automatic change will be effected. v l

Subsequentlmean automatic change from a high Aspeed gear ratio to an intermediate speed gear'- ratio, will be effected when the speed of rotation of the driven member |48 falls below that necessaryl splined to the driven shaft 22.

The transmission illustrated in Fig. 2 is adapted to provide a free wheeling drive in all forward speeds or a positive drive in all forward speeds, and is further adapted to permit a change from a free wheeling to a. positive drive or from a positive drive to a free Awheeling drive and/0r from one driving ratio to another driving ratio at the same time. Movement of the overrunning clutch 18 to mesh the teeth 84 thereof, with the teeth |36, is adapted to provide. an intermediate free wheeling drive between the driving shaft 38 and the driven shaft 22, and in effect locks out the automatic clutch |58. Further movement of the overrunning clutch 18 to the right until the teeth 64 carried by the sleeve 58 mesh with the teeth |38 carried by the gear |38 is adapted to provide a positive or two-way intermediate drive between the driving shaft and the driven shaft. The automatic clutch |58 will not be operable when the positive intermediate speed drive is connected.

, As previously described, movement of the overrunning clutch '18 to the left until the teeth 84 thereof mesh with the teeth 34 of the intermediintermediate to a high speed drive when the speed of rotation of the driven shaft attains a predetermined rate. The high speed drive effected through the automatic clutch will be a free wheel'- ing drive because of the interposition of the overrunning clutch 48 between the driving shaft and the automatic clutch |58. Further movement of the sleeve 58 to the left, will unmesh the teeth 84 and |34 and will mesh the teeth 38 carried on the forward end of the sleeve 58 with the internal teeth |68 on the driving member |42 of the overrunning clutch |48 to provide a positive high speed drive,between the driving and driven shaft 38 and 22, respectively.

`A change in the driving ratio from a positive high to a free wheeling high may be effected by merely moving the sleeve sufficient to disengage teeth 60 and |60 and by engaging teeth 84 on the overrunning clutch i0 with the teeth |34 on the intermediate speed gear |30, assuming that the speed of rotation of the driven shaft 22 is sufficient to maintain the bolts 46 in their outward or projected position. The sleeve 50 may be `moved further to the right to mesh teeth 84 with teeth |36 to provide a free wheeling intermediate speed drive between the driving and `driven shaft 36 and 22, respectively. Movement of the sleeve 50 to the right as far as possible will mesh the teeth 64 on the sleeve 5i) with the teeth |36 on the intermediate speed gear |30 to provide a positive intermediate speed drive between thev driving and driven shaft. In changing from a positive drive to a free Wheeling drive, or from a free wheeling drive to a positive drive, in the same geary ratio, it vwill be necessary to release the torque between the intermeshing teeth before a change may be effected, and this may be accomplished by a momentary ciosing oi the engine throttle.

A change from a positive high to a positive intermediate or from a positive intermediate to a positive high, may be effected without the necessity of disengaging the engine clutch because it is necessary to go thro-gh the free wheeling drive positions in ordento make such change and for that reason a temporary reduction of the engine speed relative to that of' the driven shaft wouid be sufficient to permit a change to be made manually. Similarly, a change from a, positive low to a positive ,intermediate may be effected without the necessity of disengaging the engineclutch, because to go from one position to the other, it is necessary togo through free wheeling low and intermediate free wheeling speeds before either of the positive speeds can be reached, and for this reason a temporary reduction of the speed of the engine, such as by closing of the engine throttle, will be suflicient to permit a change in the driving ratio to be effected.

While several specific embodiments of our, invention have been illustrated and described, it must be appreciated that many modifications may be made in the construction thereof without departing from the scope of the invention, an'd for that reason we do not desire to be limited to any particular form or arrangement except in so far as such limitations are included in the following claims:

1. In a transmission for connecting the driving wheels of an automotivvehicle to the engine tiiereof in a plurality of drives, the combination of a driving shaft having a clutch unit mounted thereon, said clutch unit including an overrunning clutch and a positive clutch "element, a driven shaft having a gear rotatably mounted thereon and connected through a train of speed reduction gearing to the driving shaft, said gear being provided with a plurality of positive clutch elements, a clutch member slidably mounted onI the driven shaft for rotation therewith and provided with means for engaging said clutch elements and said overrunning clutch for providing a plurality of driving connections between said shafts, said means including a positive clutch element engagaile with a positive clutch element on said gear to provide a positive low speed drive, a second positive clutch element engageable with' the positive clutch element of saidclutch unit to provide a. positive high speed drive, a; free wheel- .si-rafts, and means carried by said clutch unit and operable responsive to variations of the speed of rotation thereof above and below predetermined rates for determining the drive between said shafts when said free wheeling clutch and one of said clutch elements on said clutch member are in engagement with clutch elements on' said gear and said clutch unit. y

2. In a transmission device for providing a plurality of drives between the engine of an automotive vehicle and the road wheels thereof, the combination of a driving shaft having a clutch unit thereon, a driven shaft having an intermediconnected through a 'train of speed reduction gearing to the driving shaft, a clutch member comprising a sleeve slidably splined to the driven shaft and an overrunning clutch carried by said sleeve, a low speed gear adapted to be driven through p, train of speed reduction gearing from the driving shaft freely mounted on said sleeve and adapted to be connected thereto either directly or through said overrunning clutch to provide a low speed 'positive drive or a low speed free Wheeling drive between said shafts, means on said intermediate speed gear for connecting the same to said sieeve either directly or through said overrunning clutch to provide an intermediate speed positive drive or an intermediate speed free wheeling drive between said shafts, clutch means on said sleeve engageable with said clutch unit for providing a high speed drive between said shafts, said clutch unit being provided with centrifugally operable means for effecting automatic changes between the free wheeling intermediate and the high .speed drive responsive to variations of the speed of rotation of said driven shaft above and below predetermined rates at such timeK as said clutch means are in engagement with said clutch unit and said intermediate speed gear is connected to said -sleeve through said overrunning clutch, andvmanipulative means for relatively moving said low speed gear andvfsaid sleeve for selecting a drive between said shafts.

3. In a transmission device, the combination of two gears lrotatable at different rates of speed and adapted to be driven from a common source, a shaft adapted to be connected to said gears to be driven thereby in a plurality or" drives, a clutch unit carried by said shaft and including a free wheeling clutch and positive clutch members, means for shifting one of said gears into opera.-

tive engagement with one of said positive clutch members and said free wheeling clutch to provide either a positive or a free wheeling drive between said shafts and said common source, means for selectively shifting onerof said positive clutch members and said free wheeling clutch of said clutch unit into operative engagement with the other of said gears to provide either a positive orY` a free wheelingdrive between said shafts and said common source, and common manipulative means for optionally actuating said shifting means.

ate speed gear rotatably mounted thereon endg()y f necd to said gears in a plurality of drives, a

clutch unit carried by said driven shaft and including a free Wheeling clutch and positive clutch members, means for shifting the slower rotating of said gears into operative engagement with one of said positive clutch members and said free wheeling clutch to provide either a positive or aa free wheeling drive between said shafts, means for selectively shifting oneA of said positive clutch members and said free wheeling clutch of said clutch unit into operative engagement with the faster rotating of said gears to provide either a positive or aree wheeling intermediate speed drive between said shafts, and means carried by said driving shaft and connectable to the driven shaft through one of the positive clutch elements of said clutch unit at such times as said free wheeling intermediate Aspeed drive is provided to provide a high speed drive between said shafts, said last mentioned means including a clutch operable responsive to variations of the speed of rotation of the driven shaft above and below predetermined rates.

5. In a transmission, the combination of a driv ing shaft, a driven shaft having an intermediate speed gear. rotatably mounted thereon, a cluster of gears connected to said driving shaft and to said gear, and clutch means for connecting the driving and driven shafts in a plurality pf drives comprising a clutch member carried by the driving shaft, a clutch member carried by said gear, and a clutch element slidably splined to the driven shaft and cooperable with said clutch members to provide a drive between each of said members and said driven shaft, said clutch element having clutch members, one of which is an overrunning clutch, which are simultaneously engageable respectively with said other clutch members, said driving shaft clutch. member being provided with centrifugally operable means for determining the drive between said driving and driven shafts when said clutch element is connected to both of said Cil clutch members, and a low speed gear freely mounted on said clutch element and engageable with certain of the clutch members thereon and with said cluster of gears for providing either a positive or an `overrunning lorw speed drive between said driving and driven shafts. l

6. In a transmission, the combination of a driving shaft, a driven shaft having a gear rotat- Iably mounted thereon, acountershaft provided with a cluster of gears and connecting said gear to the driving shaft, an elongated sleeve slidably connected to the driven shaft and provided with positive clutch members and a one-way for providing positive and free wheeling drives between said driving and driven shafts in low speed, and common means for actuating said shifting means.

7. In a transmission, the combination of a drivf ing shaft, a driven shaft having a gear rotatably clutch, a clutch element carried by the driving shaft and provided with a positive clutch member and a one-way clutch, clutch members provided on said gear, means for shifting said sleeve for selectively coupling a clutch member and said one-way clutch on said sleeve with certain of said clutch members on said gear for providing positive and free wheeling drives in intermediate speed. said means being operable for shifting said e sleeve for selectively engaging certain of the clutch members thereon with said positive clutch members or said one-way clutch provided on said driving shaft clutch element for providing positive and free wheeling drives in high speed, a low speed gear freely mounted on said sleeve adapted to be connected to said cluster of gears and provided with clutch members, means forI shifting said low speed gear for selectively engaging the clutch members thereon with a clutch member and said one-way clutch on said sleeve mounted thereon, a countershaft provided with a cluster of gears and connecting said gear to the driving shaft, an elongated sleeve slidably connected to the driven shaft and provided with positive clutch members and a one-way clutch, a clutch element carried by the driving shaft and provided with a positive clutch member and a one-way clutch, clutch members provided on said gear, means for shifting said sleeve for selectively coupling a clutch member and said one-way clutch on said sleeve with certain of said clutch members on said gear for providing positive and free wheeling drives in intermediate speed, said means being operable for shifting said sleeve for selectively engaging certain of the clutch members thereon with said positive clutch members or said one-way clutch provided on said driving shaft clutch element for providing positive and free wheeling drives in high speed, a low speed gear freely mounted on said sleeve adapted to be connected to said cluster of gears and provided with clutch members, means for shifting said low speed gear in one direction for coupling the clutch members thereon with a clutch member and said one-way clutch on said sleeve forproviding positive and free wheeling drives between said driving and driven shafts inflow speed, said shifting means being operable for shifting said gear in the other direction for meshing a clutch member thereon with another of said clutch members on said sleeve to provide a reverse drive between said driving and driven shafts, and common means for actuating said shifting means.

8. A transmission mechanism providing a plurality of drives between the engine and the road wheels of an automotive vehicle comprisingthe combination of a. drivingshaft having a high speed clutch member thereon, a driven shaft having an intermediate speed gear rotatably mounted thereon and connected through a train of speed reduction gearing tothe driving shaft, a clutch member comprising a sleeve slidably splined to the driven shaft and an overrunning clutch carried by said sleeve, a low speed gear adapted to be driven through a train of speed reduction gearing from the driving shaft freely mounted on said sleeve and adapted to be connected thereto either directly or through said overrunning clutch to provide a low speed positive drive or a low speed free wheeling drive between said shafts, means on said intermediate speed gear for connecting the same to said sleeve either directly or through said overrunning clutch to provide an intermediate speed positive drive -or an intermediate speed free wheeling drive between said shafts, means on said sleeve engageable with said high speed clutch member for providing a lpositive high speed drive between said shafts, and manipulative means for moving low speed drive between said shafts, means for shifting another of said members of said clutch unit into engagement with the faster rotating of said gears to provide an intermediate speed drive between said shafts, and means carried by the driving shaft and connectable to the driven shaft. through one of the clutch members of said clutch unit to provide a high speed drive between said shafts.

10. A transmission mechanism having in combination a driving shaft, a driven shaft having an intermediate speed gear rotatably mount` ed thereon, gearing connected to said driving,

shaft and to said gear, clutch means for connecting the driving and dr1ven shafts in a plurality of drives comprising a clutch member carried by the driving shaft, a clutch member carried by said gear, and a clutchy element slidably splined to the driven shaft and cooperable with* said clutch members to provide a drive between each of said members'and saiddriven shaft,- and a low speed gear freely mounted on said clutch elementY and engageable therewith and with said 'i gearing for providing a low speed drive between said 'driving and driven shafts, said clutch element comprising a part of a one-way clutch, another 'part of which 'is provided with means whereby it may be selectively engaged with the clutch member on said first mentioned gear and with said low speed gear.

11. A variable speed power transmitting mechanism having in combination a driving shaft having mounted thereon an overrunning clutch provided with clutch members for provid-` ing positive and free wheeling drives, a driven shaft having rotatably mounted thereon a gear connected vto said driving shaft through a train of gears, and slidably mounted thereon an overrunning clutchprovided with clutch members for providing positive and free wheeling drives, and shifting means for moving said driven shaft overrunning clutch to selectively couple the clutch members thereon with eithersaid gear or the clutch members on said driving shaft overrunning clutch respectively for providing selective relative low and high speed free wheeling and positive drives between said shafts.. and an automatic clutch mechanism operatively disposed between one of the clutch members of the driving shaft Yoverrunning clutch and said driving shaft.

12. A variable speed power transmitting mechanism having in combination a driving shaft having mounted thereon an overrunning clutch provided with membersi'for providing two-Way and one-way drives, a driven shaft having rotatably mounted thereon an intermediate speed' gear connected to said driving shaft through a train of gears, and slidably mounted thereon an overrunning clutch provided with clutch members for providingtwo-way and one- Lway drives, a low speed gear slidably mounted on onefof the clutch members of said driven shaft overrunning clutch and adapted to be connected selectively to said clutch members of said overrunning clutch respectively andA simultaneously therewith to one of the gears of said train of gears for providingLone-way or two-way low speed drives between said shafts, and shifting means for moving said clutch members ofthe driven shaft overrunning clutch selectively or the members of said driving shaft overrunning clutch respectively for providing selective intermediate and high speed free wheeling and positive drives between said shafts, and for moving said low speed gear into cooperative relationship with said driven shaft overrunning clutch members and said train of gears.

13. In a transmission device for providing a plurality of drives between the engine of an automotive vehicle and the road wheels thereof, the combination of a driving shaft having a clutch unit thereon, a driven shaft having a gear rotatably mounted thereon and driven from said driving shaft, a clutch mechanisminclude ing a sleeve slidably splined to the driven shaft,

14. In a. transmission,` the combination of two drivingr elements adapted to be driven at different rates from a common source, a shaft adapted to be connected to said driving elements to be driven thereby, a clutch unit slidably mounted on. Ysaid shaft and including positive clutch elements and an overrunnmg clutch, means for selectively shifting one of said driving elements into operative engagement with said overrunning clutch and said positive clutch elements, means for selectively shifting said positive clutch celements and said overrunning clutch into operative engagement with the other of said driving elements, and common means operable for optionally actuating said shifting'means.

15. In a device of the class described, the combination of a driving shaft having a clutch unitmounted thereon, said clutch unit including a clutch element of a disconnectable clutch, a driven shaft having a gear rotatably mounted thereon and connected to be driven by said driving shaft through a train of gears, said gear becluding a 'positive clutch element engageable with a positive clutch element on said gear to provide a positive low speed drive, a free wheeling clutch engageable with one of said positive clutch elements on said gear to provide a free wheeling low speed drive, a positive clutch element engageable with the clutch element of said clutch unit at such time as said free wheeling low speed drive is provided, and means carried by said clutch unit and operable responsive to variations of the speed-of rotation thereof above and below predetermined rates for determining the drive between said 'shafts when the free wheeling clutch and one of said positive clutch elements are in engagement with the clutch element on said gear and said clutch unit.

CARL F. RAUEN. REX E. KELLER.

to cooperate with said intermediate speed gear` 

